一、直接写出得数。
20.03÷0.1= 10÷0.1-0.1= 2÷0.2-1×0.8=
6.4+4.6= 47+0.68+0.53= 1.25×16=
1.2×0.5÷1.2×0.5= 10-0.24×5 = 3.5÷3.5-0.35=
(7-7)÷10= (5.7+5.3)×0.2 = 0.35+7.5-0.65=
二、递等式计算。(能巧算的要巧算)
小学五年级数学家庭作业题：[0.31×8+(1-0.74)]÷0.1
25.505-1.56+44/100
[1÷( 4.1-4.09 )]×0.49+0.51 0.58×1.7+1.7×1.42+8.3×2
154.45-(5.46+54.45)-4.54
三、解方程
3×1.8+3 X =6 12-X÷2=8
3(8+X)÷2= 18 3.5X – 2(X + 5) = 8
(10 X-90+2 X)÷2=75